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MJ- Foundations 2 Exam 2 > Conduction disorders > Flashcards

Flashcards in Conduction disorders Deck (89)
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1
Q

What do the PQRST of an ECG represent

A
P: atrial depolarization 
PR: AV node delay
QRS: Ventricular depolarization 
ST: beginning of repolarization
T: Ventricular repolarization
2
Q

“How to read a rhythm strip”

A

Assess rate
Regular or irregular
Wide or narrow QRS
P wave to QRS relationship

3
Q

What is the big box method for counting HR

A
300
150
100
75
60
50
(5 boxes= 1 second)
4
Q

What is bradycardia due to

A

defect in impulse formation (SA) or impulse conduction (heart block)

5
Q

What constitutes “NSR”

A

rate 60-100
one P for every QRS, one QRS for every P
P waves have same morphology
QRS (in same leads) have same morphology

6
Q

What are symptoms of rhythm disorders

A

fatigue, palpitations, syncope, dizzy spells

7
Q

Whats important to check on PE

A

thyroid exam; hypothyroid can cause bradycardia

Hyperthyroid can cause arrhythmia

8
Q

What must you fix in order to correct chronic hypokalemia

A

Mg levels

9
Q

What is the initial survey of ACLS

A

Circulation
Airway
Breathing

10
Q

What are the class I anti-arrhythmic drugs

A

Na channel blockers;

1a: Mod Na block, some K & Ca. Prolong QRS
1b: weak Na block. Min ECG changes. used for Ventricular arrhythmias
* 1c: Strong Na block. wide QRS, SA node depression. NOT for CAD

11
Q

What are the Class II anti-arrhythmic drugs

A

Beta blockers: decrease sinus rate, prolong PR

12
Q

What are the Class III anti-arrhythmic drugs

A

K channel blockers: prolong QT

*amiodarone prolongs QT but side effects aren’t as bad

13
Q

What are the class IV anti-arrhythmic drugs

A

Ca channel blocker: decrease sinus rate, prolong PR

decrease contractility and cause edema

14
Q

What are other anti-arrhythmic drugs

A

Digoxin: increase vagal tone/ AV block
Adenosine: AV node blocker (half life 10 seconds)

15
Q

What is sick sinus syndrome

A

chronic SA node dysfunction diagnosed by symptoms (brady, sinus arrest, tacky-brady) plus ECG findings)
-Usually d/t fibrosis form aging

16
Q

What is sinus bradycardia

A

Normal rate and rhythm but HR under 60

Caused by fibrosis, acute injury, or med s/e

17
Q

What are symptoms of bradycardia

A

fatigue, SOB, syncope

18
Q

When would you place a pacemaker in a bradycardia patient

A

If symptomatic and d/t irreversible cause

19
Q

How do you treat sick sinus syndrome

A

Treat tacky if sx
stop offending agents if brady
Permanent pacemaker to control tachy-brady

20
Q

What is sinus arrest

A

failure of sinus node to initiate impulse causing pause >2 seconds

21
Q

When would you pace a sinus arrest patient

A

if pause is > 6 seconds

22
Q

What is tachy-brady syndrome

A

intermittent fast and slow rates from SA node or atria (<60, >100)
-periods of AFib,

23
Q

When would you pace a tachy-brady patient

A

If Afib is present as well

24
Q

What is first degree AV block

A

PR interval >200 sec (one big box)

patient asymptomatic, no treatment

25
Q

What is second degree AV block, Mobitz I

A

Wenkeback! progressive prolongation until failure to conduct and ventricular beat dropped
site of block is in AV node

26
Q

How do you treat Wenkebach

A

Not dangerous, so no treatment

usually asymptomatic

27
Q

What is second degree AV block, Mobitz II

A

Fixed PR interval, but dropped QRS
Block is in the HIS (below AV)
EMERGENCY! can lead to complete heart block

28
Q

What is complete heart block

A

no conduction from atria to ventricles
P wave independent form QRS with ventricular escape rhythm
EMERGENCY! must pace

29
Q

What are symptoms of complete heart block

A

syncope, SOB, HF, fatigue

30
Q

What are QRS width measurements of bundle branch blocks

A

Incomplete: 0.10-0.12
Complete: 0.12 or more
(wider QRS= more extensive block)

31
Q

How do you treat a bundle branch block

A

No treatment

but look further in ECG to find other indicators for conduction problems

32
Q

What is RBBB

A

Rabbit ears; LV depolarizes first, then RV (passively)

Can have RAD

33
Q

What does a LBBB look like on ECG

A

V1: negative, big Q wave
V6: positive with LAD
ST and T waves usually opposite (if Q is largely downwards, ST will be elevated)

34
Q

What can you not diagnose if the patient has LBBB

A

an MI! Because ST will be elevated if Q is negative

LBBB associated with underlying cardiac dz until disproven

35
Q

What is always indicated in a tachy patient that is NOT hemodynamically stable

A

Shock!! (light em up like a christmas tree……. smh)

36
Q

When should you NOT use adenosine

A

If patient has WPW or is in Afib

if block is not in AV node, adenosine wont do anything

37
Q

What is a PAC

A

early atrial depolarization with different P wave morphology (coming from different site)

38
Q

What are symptoms of PAC

A

usually asymptomatic but can cause palpitations

39
Q

How do you treat PAC

A

BB or CCB for symptoms.

dont need to treat if asymptomatic

40
Q

What is SVT

A
narrow QRS (140-120 bpm) due to accessory pathway
cause palpitations and syncope
41
Q

What does SVT look like on ECG

A

P wave morphology different but buried in QRS

42
Q

How do you treat SVT

A

Unstable: cardioversion
Acute setting: Adneosine and vagal maneuver
**First line tx: ablation
anti-arrhythmics BB CCB for long term

43
Q

What is WPW syndrome

A

Type of SVT- Conduction goes through accessory pathway AND AV node. Can lead to FATAL Afib (sending into VFib)
To be syndrome, must have delta wave, Sx, and SVT

44
Q

What is seen on WPW ECG

A
Delta wave (slurred upstroke of QRS)
Narrow PR
In tachycardia, delta wave disappears
45
Q

How do you treat WPW

A

same as SVT: cardioversion, adenosine, BB, CCB, anti-arrhythmics

46
Q

If patient has WPW plus AFib, what should you avoid

A

AV node blockers (digoxin, adenosine)

47
Q

What is AFib

A

No discernible P waves (300-600 bpm)- Irregularly irregular. Ventricles can fire normal or 100+
Associated w/ other heart disease, do thorough workup

48
Q

What are RF for AFib

A

age, HTN, CAD, valve dz, obesity, sleep apnea

49
Q

What are symptoms of AFib

A

asymptomatic

fatigue, dyspnea, CP, palpitations, syncope, HF

50
Q

What will you see on AFib ECG

A

QRS morphology same but can vary in interval length

P waves not discernible and irregular

51
Q

What are the 3 types of AFib

A

Paroxysmal: terminates spontaneously w/in 7 days
Persistent: fails to terminate after 7 days
Longstanding persistent: longer than 12 mo
Permanent: talk about rhythm treatment
-Valvular AFib: patient also has mitral stenosis or rheumatic valve dz

52
Q

What is the CHADSVASC scoring system

A
Risk stratification for CVA (stroke): 
C: congestive HF
H: HTN 
A: age 65-74 (1)
D: diabetes (1)
S: stroke (2)
V: 
A: Age 75+ (2)
SC: Sex, female (1)
53
Q

How do you read a CHADSVASC score

A

2+ qualify for anticoagulation (NOAC/Warfarin)

1: grey zone, talk to patient depending on points
0: aspirin

54
Q

Who does CHADSVASC not apply to

A

Valvular Afib patients

They require WARFARIN (only)

55
Q

What is warfarin

A

Vitamin K antagonist
takes 2-3 days to be theraputic (higher doses dont help)
*only anticoag for valvular Afib and mechanical heart valves
Reversible with vitamin K

56
Q

What is NOAC

A

novel oral anticoagulant, renally cleared
$$$- but no monitoring!
Onset in 2 hours

57
Q

What are the types of NOAC

A

Direct thrombin inhibitor

Factor Xa inhibitor (Eliquis best safety profile)

58
Q

What are contraindications to taking anticoagulants

A

Bleeding
Previous ICH
thrombocytopenia
severe HTN

59
Q

What is the treatment of Afib

A

Acute: AV node blocker (metoprolol, diltiazem, digoxin)
Cardioversion (24-48 hr window if not on anti-coags- do TEE to check for LAA thrombus)
Anticoag: all undergoing cardioversion, regardless of CHADSVASC (& 4 wks after)

60
Q

How can you control rhythm and rate in AFib

A

Rhythm: anti-arrhythmic drug, catheter ablation, surgical maze
Rate: BB, CCB, digoxin (AV node block)- pacemaker or AV node ablation for permanent AFib

61
Q

What is atrial flutter

A

Short re-entrant circuit in RA going at 300 bpm, but ventricular response is normal (2:1, 3:1, 4:1)
Carries risk of CVA, assess chadsvasc

62
Q

What does na atrial flutter ECG look like

A

SAW TOOTH PATTERN in inferior leads (II, III, aVF)

-Atypical flutter doesn’t have saw tooth

63
Q

What are the symptoms for atrial flutter

A

same as AFib: fatigue, dyspnea, CP, palpitations

64
Q

How do you treat Atrial flutter

A

Acute: cardioversion/TEE
Chronic: catheter ablation
-Class Ic or III anti-arrhythmic if patient cant do ablation

65
Q

What is atrial tachycardia

A

tachy from atria but not SA node. Faster than SA, so it takes over (140-220). Benign
Caused by atrial scarring/drugs (digoxin) and can lead to AFib

66
Q

What can you find on Atrial tachy ECG

A

P wave hard to find (in T waves) but rhythm is regular

67
Q

How do you treat Atrial tachycardia

A

treat based on symptoms (BB, CCB, class Ic or III)
Adenosine won’t work (not from AV node)
Rarely need cardioversion

68
Q

What are symptoms of Atrial tachy

A

palpitations

69
Q

What is a PVC

A

Early ventricular depolarization causing wide QRS WITHOUT preceding P wave (bigeminal or trigeminal patterns)
Can be monomorphic or polymorphic

70
Q

What are symptoms of PVC

A

palpitations

71
Q

What will you see on PVC PE

A
irregular pulse 
Effective bradycardia (electric beat on ECG w/o perfusion or pulse to match)
72
Q

How do you treat PVCs

A

holter monitor to determine burden of PVC
Initial: BB or CCB
Antiarrhythmics (sotalol)
If PVC causes cardiomyopathy, Ablation

73
Q

What is VTach

A

3 or more PVC (160-200 bpm), usually d/t CAD/MI causing scar
Non sustained: >3 beats, less than 30 seconds before spontaneous termination
Sustained: >30 seconds, need cardioversion

74
Q

What are symptoms of VTach

A

syncope, dizziness, palpitations, CP

May be stable or unstable on PE

75
Q

How do you treat VTach

A

full cardiac work up and cardiac cath

76
Q

What are the types of VTach

A

Monomorphic: due to re-entrant circuit in ventricle d/t scar
Polymorphic: more electrically unstable, ominous (similar to Torsades and VF)

77
Q

Is wide complex tachycardia always VT

A

yes until proven otherwise. Check 12 lead

If unstable, cardiovert!

78
Q

How do you treat VT acutely

A

If unstable, cardiovert

Stable with pulse: acutely, IV amiodarone or BB. electrical cardioversion if SR not restored

79
Q

How do you treat VT chronically

A

BB
ICD
Class III for long term anti-arrhythmic use
If all fails, ablation

80
Q

Do anti-arrhythmic improve survival

A

NOOOOOPE

81
Q

What is Torsades

A

A polymorphic VT with LONG QT INTERVAL
“twisting” QRS along isoelectric baseline
**Can occur in complete heart block

82
Q

How do you treat Torsades

A

Emergent Cardioversion, can lead to sudden cardiac death
**Use Mag after cardioversion
If unstable, defibrillate

83
Q

What are symptoms of Torsades

A

Syncope!

patient may be hemodynamically unstable

84
Q

Why would you want to temporarily pace a Torsades patient at 100 bpm

A

To shorten the QT interval

85
Q

How do you treat long term Torsades

A

Long term BB and ICD

stop offending agents

86
Q

What is VFib

A

Pulseless, no discernable ventricular activity (200-300!)

If untreated, causes systole (DEATH)

87
Q

What must you emergently do in VFib

A

Defibrillate! Epinephrine, chest compressions, secure airway
(Rapid resuscitation to prevent anoxic brain injury)

88
Q

What is the most common cause of VFib

A

CAD

89
Q

How are VFib patients most commonly found

A

Found down, or witnessed out of hospital arrest (3-5% survival)